Switch for continuous outlet



April 1959 v E. H. RANBERRY. 2,882,374

- sgviw'cn FOR CONTINUOUS OUTLET {Sheets-Shed 1 Filed Aug; 23, 1956 267e I 26 i j j I 28 I 35' 3 2s es as F fi 53 H as F.

\ 1 Y INVENTOR 1 76;]. EDGAR, H. GRANBER RY ATTORNEYS P 1959" E. H.GRANBERRY SWITCH FOR CONTINUOUS OUTLET 4 Sheets-Sheet 2 Filed Aug. 23,1956 R mY R .R VE m8 N A R G H R A G D E ATTORNEYS 'AP 1959 I E. H..GRANBERRY SWITCH FOR CONTINUOUS OUTLET 4 Sheets-Sheet 3 Filed Aug. 2:,195a INVENTOR EDGAR H. GRAN BERRY E. H. GRANBERRY SWITCH FOR CONTINUOUSOUTLET Apfil 14, 1959 I 2,882,374

Filed Aug. 25, 1956 4 Sheets-Sheet 4 iii MOTOR STARTER I MOTOR CONTROLSWITCH L/I4Z FIG. 1.5.

INVENTOR EDGAR H .GRANBERRY ATTORNEYS SWITCH non CONTINUOUS OUTLET EdgarH. Granberry, Shawmut, Ala., assignor, by mesne assignments, toParks-'Cramer Company, Fitchburg, Mass, a corporation of Massachusetts I4 Application August 23, 1956, Serial No. 605,783

' 11 Claims. (Cl. 200-168) This invention relates to electrical switchmeans, and particularly to switches adapted for use with continuousoutlet constructions. The invention relates further to textilemachinery, and to improved electrical stop motions therefor. Theinvention has particular application to textile machines having buildermotions, such as fly frames.

A principal object of the invention is the provision of novel switchstructure adapted for adjustable and removable attachment to continuouselectrical outlet constructions, of the type exemplified by Frank PatentNo. 2,170,- 299, issued August 22, 1939.

Another object of the invention is the provision of an improved stopmotion for textile machines, utilizing continuous electrical outletshaving bus bars which are enclosed and protected, to which a pluralityof switches may be readily attached at desired positions along thelength thereof.

A further object is to provide electrical stop motions for textilemachines including builder motions, wherein the stop motion includessimplified means actuated by the tumbler shaft of the builder motion toprevent operation of the stop motion during periods of reversal. Theinvention also includes, preferably, provision of structure in thebuilder motion for deactivating the stop motion circuit prior to periodsof reversal, to insure that the machine is not carried by momentum orinertia to an undesired stopping point.

Still another object is to design an improved stop motion of outstandingsimplicity and versatility, which is inexpensive to manufacture andapply to textile machines.

Further objects of the invention will be in part obvious and in partpointed out hereinafter.

The invention and the novel features thereof may best be made clear fromthe following description and the accompanying drawings in which:

Figure 1 is a diagrammatic illustration of an exemplary fly frameincorporating the present invention;

Figure 2 is a fragmentary elevational view of the frame of Figure 1,taken on the line 2-2 thereof;

Figure 3 is an enlarged front elevational view of a preferred switchconstruction, with the cover plate thereof removed;

Figure 4 is an enlarged sectional view through the switch of Figure 3,taken on the line 44 thereof;

Figure 5 is a side elevational view of the rotatable con-'1 tact andprong of the switch of Figure 3;

Figure 6 is an end elevational view of the element of Figure 5, viewedfrom the right hand side thereof;

Figure 7 is an elevational view of the fixed prong of the switch;

Figure 8 is an end elevational view of the elementof- Figure 7, viewedfrom the right hand side thereof;

Figure 9 is a perspective view of a modified form of the movable contactof the switch;

Figure 10 is a fragmentary and enlarged diagrammatic illustration urel;

of the builder motion of the machine ofv Fig- "2,882,374 Pa nt d Apr, 419 9 2 a Figure 11 is a top plan view of the gap gear of the buildermotion of Figure 10;

Figure 12 is a fragmentary perspective view of one of the builder jawsof the Figure 10 builder-motion;

Figure 13 is a top plan view of the tumbler shaft cam disc of Figure 10,illustrating its relationship to an associated stop motion circuitswitch; I Figure 14 corresponds to Figure 13, illustrating how ever amodification of the cam disc; and h Figure 15 is an exemplary circuitdiagram for the machine of Figure 1. v Referring to the drawings, andparticularly to Figure 1 thereof, 20 indicates the frame of aconventional roving or fly frame, having the usual draft rolls 22mounted thereon. From the draft rolls 22 a row of strands 24 extends toone or more rows .of flyers 26 to be'woun'd on bobbins 28 in the usualmann'en, As is conventional, the bobbins 28 are journaled in avertically reciprocating or traversing carriage 30. A driving spindle 32extends upwardly to each flyer 26, passing through the carriage 30 andthe associated bobbin 28, and a hollow spindle 34, coaxial with andenclosing the driving spindle 32, is' provided for driving each bobbin28.' The bobbins are reciprocated relative to the flyers by the carriage30, to wind the strands 24 on the bobbins 28 in successive layers ofprogressively diminishing length, in the well known manner to producepackages 35 having cone shaped ends 36.

Reciprocation of the carriage 30 is effected by a conventional buildermotion, which includes at; bracket 38 or the like reciprocable with thecarriage'30, and in which is journaled a shaft 40. The shaft 40, betweenthe legs of bracket 38, is provided with oppositely threaded sections,whereby the builder jaws 42, 44 may be moved in unison in oppositedirections. As will be understood, intermittent rotation of the shaft 40during the building of packages on the bobbins 28 effects progressivemovement of the builder jaws toward each other, to progressivelydecrease the amplitude of the bobbin carriage reciprocation. Disposedadjacent the shaft 40 is the usual tumbler shaft 46, which carries abuilder dog 48 having arms 50, S2 cooperative with the builder jaws. Atits upper end the tumbler shaft 46 carries the usual gap gear 54(Figure' 10) adapted to be driven by the bevel gear 56 fixedon the topor upper cone shaft 58 of the machine. The upperv cone shaft 58 rotatescontinuously, and the gap gear 54 is provided with diametrically opposedperipheral gaps 60 therein, aligned generally with the builder dog arms50, 52, to permit rotation of the upper cone, shaft gear 56 while thegap gear 54 remains stationary. 'As iswellj' I known, the tumbler shaft46 is spring biased to rotate,

but is prevented therefrom by engagement of either of the builder dogarms with the cooperative builder jaw. As' each builder dog arm ridesover the end of the engaged builder jaw, by reason of the reciprocationof the builder jaws, the tumbler shaft is rotatedwhereby the gap gear 54is engaged in driving relationship by the gear 5,6 ,and:

thereby rotated through substantially 180, at which point the oppositebuilder dog arm engages the cooperative builder jaw and precludesfurther rotation, for the moment,

of the tumbler shaft. At such time, the bevel gear again rotates free ofthe gap gear 54, in one of the gaps 60 thereof. Each movement of thetumbler shaft 46, as will be understood, effects reversal in directionof the carriage 30, and decreases the length of its stroke.v

It is desirable to stop the machine in the event any strand 24 breaks orbecomes undulyslack, and for such purpose each strand between the draftrolls 22 and the flyers 26 may be enclosed by the eye 62 of a drop wire,64, which forms part pf an'electrical stop motion. Coa ventionalelectrical stop motions includean open switch present invention isillustrated in Figures ,3 to 8.

associated with each .dropwire, the switches being arranged in parallel,whereby movement of any drop wire from or beyond a predetermined pointwill close a circuit and thereby efiect stoppage of the machine.

"In accordance with the present invention, continuous electrical outletstructures are employed in the stop motion and are arranged-transversely.of the strand row. As-illustrated in 'Figure l, a continuous outlet 66may be mounted on the depending flange 68 of frame 20. Preferably, thecontinuous outlet is of the type manufactured and sold by theBulldogElectric Products Co. of Detroit, Michigan, under the trademarkElectrostrip. As bestshown in Figure 4, the continuous outlet 66comprises a continuous back wall structure 70, having reversed edgeflanges 72;.substantially enclosing and retaining upper and lower bus.bars 74. The flanges 72 define between theme receiving slot76 (Figure3) into which suitably formed electrical components may be inserted andbrought into electrical connection with the bus bars. Continuous outletsof this type-are well known and widely used, .andcommercially availablein extended lengths. They are advantageous in that electrical elementsmaybe readily engaged thereto at any desired point or points along thelength .thereof. Additionally, the bus bars :a'reefiectively protectedfrom inadvertent contact. The continuous outlets are readily mounted, asby conyentionalscrews or-bolts, extending through the back Wall 70thereof into supporting structures. Continuous electrical outlets ofthis type have been found to be useful in stopmotions of 'fiyfrarnesandother textile machines, inthat they are readily andinexpe'nsivelyapplied to existing machinery and form a .convenientstructure .for usewith thenovel switch-means of thepresentinvention.

A preferred switch means in accordance with the As there shown, theswitch indicated generally as 78 comprises'a casing '80 having ,a backwall'82 and side walls 8d integral therewith. The casing preferably isconstructed of suitable electrically non-conducting material. A ,"coverplate v86 of conducting or non-conducting material, .is adapted to'sealtightly with the side walls 84. A generally rectangular metal prong 88is mounted externally on the 'casing'back wall 82, adjacent the lowerend thereof, being provided, .as shown in Figure 7, witha plurality of.contacnpoints 90 adapted tomake firm electrical Contact with .a'busbar. As shown in Figures 4 and 8, the outer portion .92 of prong 88 isangulated slightly with respect to the base portion thereof. The prong88 is mounted on the rear wall of the casing by means of rivets 94extending through the wall 82, and engaging a metal bar 96 disposed onthe inner surface of the casing wall.

' Above the metal bar 96 and prong 88, a cylindrical contact 98 of metalor the like is journaled for rotation in the casing wall. A I-n'ut 1.00threadably engaged to the inner end of contact98limits movement of thecontact in outward direction, and the outer end of contact 98 isprovided with a metal prong .102, having a cam edge 104, bestillustrated in Figure .6.

A stub shaft 106, also of metal or other electrically conductingmaterial, is journaled for rotation in the casing cover plate 86 ingeneral alignment with the metal bar 96 and parallel to contact 98, andthe reducedinner end 108 of shaft 106 isjournaled ina bore 110 providedtherefor centrally of thelmetal bar 96, the casing back wall 82 beingprovided with a recess 112 adapted to receive the shaft end 108..Amovable electrical contact 114 is fixed on the shaft 1.06, said contacthaving a flat .116 on its upperside, spacedsomewhat from thefixedcontact 35. as shown. As'will .be understood, rotation of the shaft 106and itscontact I114 in either direction from the position illustrated in.Figure 3 will bring the movable contact .114 into engagement with .thefixed contact 98, establishing electrical-connection therebetweem .Thecutmandamus .etsmb .shaft .106, that the and aasaa'rs.

protruding from the coverplate v86, is drilled or otherwise adapted toreceive the end of a drop wire 64, and means, such as set screw 118, maybe provided to adjustably engage the drop wire thereto.

The switch 78 is adapted to be conveniently and quickly applied to thecontinuous outlet 66 at any desired position along its length. For thispurpose, the cover plate 86 and the stub shaft 106 mounted therein areremoved from the switch, and the contact 93 is rotated, as by means ofits kerf or slot 120, approximately from the position illustrated inFigure 4, whereby the prong 102 thereof is disposed longitudinally ofthe switch casing. The fixed prong 88 may then be positioned over thelower flange 72 of the continuous outlet 66, at any position therealong,this positioning being facilitated by the angulation of the fixed prong.The switch casing may then be rocked into firm contact with the outerface of the continuous outlet, whereby the movable prong 102 is disposedin the slot 76 rearwardly of the upper flange of the outlet. By means ofslot 120, the contact 98 may then be rotated to bring the cam edge 104of prong 102 into firm engagement with the upper bus bar 74 of theoutlet, this action being elfective to force the contact points 90 ofprong 88 into similarly firm contact with the lower bus bar 74 of theoutlet and also being effective to securely retain the switch inassembled relation with the outlet. As will be understood, the initialdisposition of the prong 102 is necessarily such that rotation thereofinto contact with the bus bar will bring the lower portion of the camedge 104 thereof initially into contact with the bus bar. The casingbeing thus locked in place, the cover plate 86 and stub shaft 106 maythen be mounted thereon, the reduced inner end 108 of the stub shaftbeing positioned in the bore 110 of bar 96 provided therefor, aspreviously noted. The cover plate may be secured tightly in place, as byscrews or bolts extending therethrough into the casing body bores 122(Figure 3),. The drop wire 64 may then be secured to the protruding endof the stub shaft 106.

Figure 9 illustrates an alternative structure for the stub shaft 106,wherein the stub shaft 106' is provided with radially extending contactpins 124, suitably mounted in the stub shaft. As will be readilyunderstood, the stub shaft is positioned with the angularly spaced pins124 disposed on either sideof the fixed contact 98, so that slightrotation of the stub shaft in either direction will cause one or theother of pins 124 to engage the fixed contact.

The switch of the invention preferably is disposed immediately below thestrand with which it will be associated, so that the engaged drop wire64 will normally be maintained in vertical, upwardly extending positionby the strand running through its eye. In such relation, the stub shaft106 and its drop wire 64 are dynamically unstable, and undue slack orbreakage of the associated strand will result in the drop wire swingingto either side.

some cases, it may be desirable to mount the switches.

78 slightly laterally or to the side of their associated strands sothatthe drop wires engaging the strands will now be normally disposed inan inclined position when the switch is open. With this arrangement, theweightof the drop wire will act continuously to urge the switch toclosed position.

I The bus bars of the continuous outlet preferably are in circuit witha'relay adapted to open the power circuit of the machine. As will beunderstood, the various switches mounted on the continuous outlet, arethereby. disposed 'inparallel, sothat the closing of any switch will beeffective to deactivate the machine.

- .In roving frames, packages 35 of the type illustrated in Figure 1 arecommonly wound with end cones 36 at .end of their traverse, since insuch case the strands are prone to run off onto the tapered cone ends,thereby introducing slack and causing loose windings which impair theusefulness of the packages. For this reason, it is desirable to insurethat the stop motion circuit is deactivated when the traversing carriageis at either end of its traverse. According to the present invention,this is accomplished in simple fashion by means of a switch 126,actuated by the tumbler shaft 46 of the builder mechanism of themachine.

As illustrated in Figures 10, 13, and 14, a cam disc 128 may be fixedlymounted on the tumbler shaft, and the switch 126 mounted adjacent theperiphery of the ,cam disc, whereby the switch arm 130 bears thereon.The cam disc may be provided with diametrically opposed recesses 132 andthe cam disc is so aligned on the tumbler shaft that the switch arm willrest in one or the other of the recesses while the tumbler shaft is atrest, that is while the builder dog 48 is held stationary by the builderjaws 42 and 44. The switch 126 normally is closed, and adapted to beopened by movement of its arm 130 out of a recess 132, whereby theswitch will be opened by movement of the tumbler shaft and be maintainedopen through each period of rotation thereof.

As illustrated in Figure 14, the cam disc 128 may be provided withdiametrically opposed lobes 134, and the switch'126' normally closedwhen its arm 130 is engaged by one of said lobes. Rotation of the camdisc will, in such case, move the engaged cam lobe away from the switcharm, whereby the switch is permitted to open and remains open untilagain closed by the opposite lobe.

The switch may be actuated in other equivalent manner,

as by flats formed in the tumbler shaft.

The switch 126, it will be understood, is normally in series with thecontinuous outlet previously described, that is, in series with the dropwire switches. An exemplary circuit diagram is illustrated in Figure 15,wherein-136 represents an electric motor for running the machine. Apower source for this motor is indicated at 138, and a conventionalmotor starter 140 and motor control switch 142 may be arranged in thecircuit for the motor 136. Suitably connected (as shown) in the powercircuit for the motor 136 are a relay 144 and a normally closed switch146, the latter being adapted to be opened by energization of a relay150 in the stop motion circuit. The relay 144 is a time delay relay,preferably an Agastat Model NE11, and is adapted to deactivate the stopmotion circuit for a predetermined period of time after the motor 136 isstarted, for a purposeto be explained hereinbelow.

'Ilhestop motion circuit may receive its power from a suitabletransformer 148, and the switches 78, 126 are arranged in series in thiscircuit as shown. The stop motion circuit includes the relay 150 foropening the switch 146 inthe main power circuit, to stop the machinewhen both the switches 78 and 126 are closed. Also arranged in the stopmotion circuit, in parallel branches as shown, are a signal lamp 152 anda relay 154. The. time delay relay 144 of the main power circuitnormally closesa first switch 156 in the branch of the stop circuit forrelay 154, and it also closes a second switch 158 in the branch of thestop circuit which includes the relay 150, the latter branch beingconnected to the branch.

that when switch 126 is opened at either end of the. traverse ofcarriage 30, that is-duringreversing periods, the stop motion circuitwill be deactivated or rendered inoperative, sothat if one of theswitches 78 is closed during such times due to slack in its associatedstrand, the motor 136 will continue to run, and the machine will not bestopped until switch 126 is closed. This occurring on termination of thereversing period.

Switch 126 may be arranged in the branch of the stop circuit containingthe relay and the switch 158, .by disposing this switch 126 betweenrelay 150 and switch 158. By reason of this disposition of switch 126,lamp 152 will burn as soon as one of the switches 78 is closed, however,the machine will not stop unless switch 126 is closed. Consequently, ifa strand becomes slackened to close its associated switch 78 duringthose periods when switch 126 is open, that is, slightly before andduring each reversing period of carriage 30, lamp 152 will burn butrelay 150 will not be energized to stop the machine until the reversingperiod has terminated and switch 126 has been closed. Thus, anindication of slack or breakage in a strand may be immediately given tothe operator under all circumstances.

If desired, a suitable temperature responsive overload switch (notshown) may be provided in the stop motion circuit for energizing therelay 150 to stop the machine in the event of an overload on thetransformer 148.

As will be understood, should any one of the normally open switches 78be closed in the manner described, between reversing periods, relay 154will be immediately energized, causing the main power circuit relay 150to be energized and open switch 146 whereby the power circuit for motor136 will be opened and the machine will stop. At the same time, the timedelay relay 144 in the main power circuit will be deenergized to openswitches 156, 158 thereby deenergizing relays 150, 154 but notinterfering with the branch circuit through signal lamp 152. By virtueof this arrangement, the signal lamp 152 will remain burning so long asswitches 78, 126, are closed, to provide a visual indication of machinestoppage, while, as is evident, the main power circuit relay 150 will bedeenergized shortly after the machine has been stopped to reclose switch146. As is well understood, the motor 136 will not be restarted by thisclosing of switch 146 since the motor control switch 142 again has to beclosed before the motor circuit will be closed.

In restarting the machine after stoppage due to slack in one or more ofthe strands, the defective strand is first repaired or corrected, andthe motor control switch is closed to close the power circuit for motor136.- The time delay relay 144 keeps the contacts 156, 158, opened for ashort period of time after the motor 136 has been restarted, for example10 seconds, to enable any slack remaining in the repaired strand to betaken up by its associated bobbin to open the involved switch 78 beforethe operation of the machine is brought under the control of the stopmotion circuit.

It has been found in practice that if one of the strands becomes slack ashort time prior to either end of the traverse of carriage 30, and stopsthe machine at this time, the inertia or the momentum of the buildermotion might be sufiiciently large to drive the carriage to the end ofits traverse. the strands 24 running over the tapered package ends 36 isagain presented. To avoid such possibility, the invention furthercontemplates the provision of means for opening the switch 126 todeactivate the stop motion circuit a short time prior to the reversal ofthe carriage 30. A preferred form of such means is illustrated inFigures 10 and 12, and includes notches or recesses 162 constructed inthe extreme opposed ends of the.

dog arm rides completely over its associated builder Should this occur,the danger of assent "i'awto reverse the carriage movement. The tumbler:46, therefore, will be permitted a slight rotation immediately beforethe ends of the carriage traverse, to cause a corresponding movement ofthe cam disc 128 whereby the switch 126 will be opened and remain in anopened position until the tumbler shaft rotates approximately 180, atwhich time the opposite builder dog arm will strike the adjacent builderjaw to prevent further rotation of the tumbler shaft. In thisconnection, it will be observed that the builder dog arms 50, 52 arerespectively provided with free outer ends 51, 53 extending in oppositeaxial directions, at right angles to the arms, whereby after each 180rotation of the tumbler shaft 46 one of these free ends will strike theflat, 'unnotched portion of the builder jaw to dispose switch arm 130 ina cam disc recess 132 for closing switch 126. Additionally, since thebase 45 of the lower builder jaw 44 is larger than the base 43 of upperjaw 42 (see Figure it should be evident that the notch 162 in the lowerjaw will be of greater horizontal dimension than the notch of the upperjaw to allow the desired slight rotation of the tumbler shaft 46 when abuilder dog arm rides off the jaw 44.

If desired, the notches 162 may be omitted from the builder jaws, andthe builder dog arms 50, 52 may be formed with similarly functioningnotches or recesses 164. Such notches may be arranged at the extremeouter ends of the builder dog arms, on opposite radial surfaces thereof,as seen in Figure 10. Once again, the notch 164 on the builder dog armwhich rides over the end of the jaw 44 is made larger than the notch inthe other arm due to the larger base of jaw 44. It will be understood,that by varying the vertical dimension of the notches 162 or 164,whichever the case may be, the time in advance of the reversing periods,at which switch 126 will open, may be varied.

Inasmuch as the gaps 60 in the gap gear 54 on thetumbler shaft 46 arenormally of such size that rotation of the tumbler shaft 46 will cause asection of gearing on gear 54 to be brought into engagement with thecone shaped bevel gear 56, these gaps 60 may have to becircumferentially enlarged to permit slight rotation of tumbler shaft 46immediately before the ends of the carriage traverse, without elfectinga driving engagement between gears 56 and 54. This is due to the factthat one of the builder dog arms will still be in engagement with abuilder jaw for a short period of time after such slight rotation of thetumbler shaft to resist further rotation thereof during this shortinterval. This enlarging of gaps 60 is readily accomplished, whennecessary, by removing one or more teeth from each gear section of thegap gear.

It will thus be seen that there has been provided by this invention astructure in which the various objects hereinbefore set forth, togetherwith many practical advantages, are successfully achieved. As variouspossible embodiments may be made of the mechanical features of the aboveinvention, all without departing from the scope thereof, it is to beunderstood that all matter hereinbefore set forth or shown in theaccompanying drawings is to be interpreted as illustrative, and not in alimiting sense.

I claim:

1. An electrical switch adapted for use with continuous outlets havingspaced bus bars protected by flanges defining a slot, comprising, acasing, metal prongs mounted externally on said casing, one of saidprongs being movably mounted, a normally fixed contact in said casingelectrically connected to said one prong and being movable to its fixedposition for securing tight engagement of said one prong to thecor-responding bus bar of a continuous outlet, and a movable contact insaid casing electrically connected to the other of said prongs,

said movable contact being movable into and out of' engagement -withsaid fixed contact.

2. A switch a. defined "in claim :1, including ashaft journaled in saidcasing engaged to "said movable Contact and extending to the exterior ofsaid casing.

3. An electrical switch adapted for use with continuous outlets havingspaced bus bars protected by flanges defining a slot, comprising, acasing, a fixed metal prong mounted externally on said casing, a metalprong rotatably mounted externally on said casing, a normally fixedcontact in said casing electrically connected to said rotatable prongand being movable to its fixed position for securing tight engagement ofsaid rotatable prong-to the corresponding bus bar of 'a continuousoutlet, and a movable contact in said casing electrically connected tosaid fixed prong, said movable contact being movable intoand out ofengagement with said fixed contact.

4. An electrical switch adapted for use with continuous outlets havingspaced bus bars protected by flanges defihing a slot, comprising, acasing having front and back walls, a fixed metal prong externallymounted on the back wall of said casing, the outer portion of said pronglying in a plane adjacent and generally parallel to "said back wall, afirst shaft extending through the back wall of said casing and rotatablymounted therein, a metal prong fixed to the outer end of said firstshaft and extend ing at right angles therefrom substantially in "theplane of said fixed prong, the inner end of said first shaftconstituting a normally fixed contact, a second shaft extending throughthe front wall of said casing and rotatably mounted therein, and acontact extending radially from said second shaft and movable into andout of engagement with the inner end of said first shaft.

5. An electric switch for use with a continuous electrical outletstructure of the type having spaced bus bars protected by flangesdefining a slot, said switch coinprising a casing, a pair of metalprongs mounted externally of said casing and adapted to engage the busbars of the continuous outlet, a normally fixed contact in said casingelectrically connected to one 'ofsaid prongs and being movable to itsfixed position for securing tight engagement of said one prong to thecorresponding bus bar of the continuous outlet, a movable contact insaid casing electrically connected to the other of said prongs, andswitch actuating means operably connected to said movable contact andmoving said movable con-' tact into and out of engagement with saidfixed contact for closing and opening said switch. 6. An electric switchfor use with a continuous electrical outlet structure of the type havingspaced bus bars protected by flanges defining a slot, said switchcomprising a casing having front and back walls, a fixed metal prongexternally mounted on the back wall of said casing, the outer portion ofsaid prong lying in a plane adjacent and generally parallel to said backwall, a firstshaft extending through the back wall of said casing androtatably mounted therein, a metal prong fixed to the outer end of saidfirst shaft and extending at right angles therefrom substantially in theplane of said fixed prong, the inner end of said first shaftconstituting a fixed contact, a second shaft extending through the frontwall of said casing and rotatably mounted therein, said second shaftbeing electrically'connected to said fixed prong, a contact extendingradially from said second shaft, and switch actuating means operablyconnected to said second shaft for rotating said second shaft to movethe radially extending contact thereon into and out of engagement withthe inner end of said first shaft for closing and opening said switch.

7. An electric switch for use with a continuous electrical outletstructure of the type having spaced bus bars protected by flangesdefining a slot, said switch com prising a casing, a fixed metal prongmounted externallyon said casing, a metal prong rotatably mounted ex-'ternally on said casing and adapted to facilitate en; gagement to thebus bars of a continuous electrical-out let, a normally fixed contact insaid casing electrically connected to said rotatable prong and beingmovable to its fixed position for securing tight engagement of saidrotatable prong to the corresponding bus bar of the continuous outlet, amovable contact in said casing electrically connected to said fixedprong, and switch actuating means operably connected to said movablecontact and moving said movable contact into and out of engagement withsaid fixed contact for closing and opening said switch.

8. An electric switch for use with a continuous electrical outletstructure of the strip type having spaced bus bars disposed adjacent tothe upper and lower edges of the strip respectively with protectiveflanges on the upper and lower edges of the strip and extending inwardlytoward each other to cover the bus bars, and the strip and protectiveflanges defining a slot; said switch comprising a casing, a pair ofmetal prongs mounted externally of said casing and adapted to engage thebus bars of the continuous outlet, a fixed contact rotatably mounted insaid casing and having an outer end rigidly secured to one of saidprongs, a movable contact rotatably mounted in said casing andelectrically connected to the other of said prongs, said fixed contactbeing adapted to be loosened and tightened for adjustably securing saidone prong in wedged engagement with the corresponding bus bar at anydesired position along the electrical outlet strip, the fixed contactwhen tightened being adapted to cooperate with said one prong to serveas the sole support for said switch on the electrical outlet strip, andsaid movable contact being movable into and out of engagement with saidfixed contact for closing and opening said switch.

9. An electric switch for use with a continuous electrical outletstructure of the strip type having overhanging flanges on the upper andlower edges of the strip extending inwardly toward each other, and busbars concealed within the junctures between the flanges and the upperand lower edges of the strip respectively; said switch comprising acasing, metal prongs mounted externally of said casing and adapted topenetrate between the flanges and the strip to engage the concealed busbars, a first shaft rotatably mounted in said casing and having an outerend rigidly secured to one of said prongs, the inner end of said firstshaft constituting a fixed contact, a second shaft rotatably mounted insaid casing and electrically connected to the other of said prongs, acontact extending radially from said second shaft, said first shaftbeing adapted to be loosened and tightened for adjustably securing saidswitch to the electrical outlet strip at any desired positiontherealong, said first shaft when tightened causing said one prong toforcibly penetrate between the strip and corresponding flange for wedgedengagement .with the respective one of concealed bus bars, said firstshaft and said one prong constituting the sole supporting means for saidswitch on the electrical outlet strip, and said second shaft beingmovable to move said radially extending contact thereon into and out ofengagement with the inner end of said first shaft for closing andopening said switch.

10. In combination with a continuous electrical outlet comprising aninsulation strip provided with inwardly extending flanges at its upperand lower edges, and spaced bus bars disposed between the respectiveflanges and the insulation strip, an electrical switch comprising acasing, externally mounted metal prongs carried by said casing, saidmetal prongs being received between the respective flanges and theinsualtion strip and adapted to engage said bus bars, one of said prongsbeing mounted for arcuate movement, means on said last-mentioned prongproviding a progressively increased degree of pressure by said prongagainst the corresponding bus bar in response to the arcuate movementthereof in one direction for tightly securing the casing of said switchto said electrical outlet with said prongs in engagement with said busbars, the arcuate movement of said prong in the op posite directionserving to loosen the securement of said casing to said electricaloutlet for removal therefrom and adjustment therealong, a fixed contactin said casing electrically connected to one of said prongs and amovable contact in said casing electrically connected to the other ofsaid prongs, said movable contact being movable into and out ofengagement with said fixed contact to close and open said switch.

11. The structure defined in claim 10, wherein said means comprises acam edge on said prong extending from a lowermost point at one end ofthe prong to an uppermost point at the other end of the prong.

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